Investigation of acoustic performance and noise reduction optimization for ventilation duct elbows with a guide vane.

Elbow noise constitutes a significant issue in ship ventilation systems. Guide vanes are commonly used to mitigate this noise, and their geometric configuration exerts a substantial influence on acoustic performance. The study concentrates on rectangular elbows utilized in cruise ship ventilation systems and systematically investigates the effects of guide vane geometry on acoustic behavior. A coupled optimization framework is established, integrating a radial basis function neural network response surface model with the fast-elitist non-dominated sorting genetic algorithm. The results indicate that an optimal low noise elbow design is realized through a combination of a shorter inlet length, a moderate outlet length, an appropriate radius, a smaller thickness, and a larger angle. The optimized guide vane enhances flow uniformity while reducing pressure drop, peak velocity, and turbulent kinetic energy. Furthermore, an 8.64 dB reduction in sound pressure level at the monitoring point is achieved. The study elucidates the influence of guide vane geometry on flow induced noise and proposes a multi-objective optimization framework for low noise design in cruise ship ventilation systems, providing both theoretical insight and practical guidance.